Power plants can use battery energy storage system (BESS) units to satisfy requests for power. Power plants can have one or more temperature controlled rooms for storing the BESS units. The temperature of an individual BESS unit can be affected by a charge and/or a discharge applied to the individual BESS unit. If the individual BESS units within a temperature controlled room have too wide a range of temperatures, then it can be difficult to determine an appropriate temperature for the temperature controlled room.